Vol. 30, pp. 13-16 January 22, 1917 



PROCEEDINGS 



OF THE 



BIOLOGICAL SOCIETY OF WASHINGTON 



TWO NEW OPHIURANS FROM THE CHINA SEA 



BY AUSTIN H. CLARK.* 



A study of the unnamed ophiurans in the collection of the 

 United States National Museum has brought to light the two 

 following hitherto undescribed species from the China Sea. 



Ophiopteron alatum sp. nov. 



The disk is 4.5 mm. in diameter, and the arms are apparently about 

 25 mm. long. 



The dorsal surface of the disk is covered with large naked radial shields 

 and naked overlapping plates, the latter extending in a narrow band 

 with parallel sides from the centre of the disk to the interbrachial border, 

 and outwardly between the radial shields in a very narrow elongate tri- 

 angle the apex of which lies at or near the base of the arms. 



The centre of the disk is occupied by a pentagonal plate with rounded 

 corners directed interradially, which has a raised and thickened border. 

 On each side of this pentagon is a large subcircular plate, the diameter 

 of which is about two-thirds that of the central plate. These five sub- 

 circular plates are separated by very small oval plates which lie on the 

 angles of the central pentagon. Beyond the subcircular plates is a 

 smaller plate, triangular in shape with the apex more or less rounded, 

 and beyond this a very narrow triangular plate which reaches nearly or 

 quite to the arm bases; these last two plates lie between the radial 

 shields. 



Following the small plates situated at the angles of the central penta- 

 gon is an oval plate which is about twice as long as broad, the longer 

 diameter lying in the interradial line, beyond which are two pairs of 

 plates, or two irregular columns of from two to four plates, reaching to 

 the spine bearing plates of the interradial border of the disk. On either 

 side of this interradial series of plates are a few plates with the greater 

 part of their surface concealed through the imbrication of the plates lying 

 within them, which delimit the straight border of the interradial plated 



strip. . ^_ 



• Published with the permission of the Secretary of the Smithsonian Institution. 

 5— Proc. Biol. Soc. Wash., Vol. 30, 1917. (13) 



